Brake servo comprising a connecting element with a defined angular position

ABSTRACT

The present invention relates to a brake booster ( 1 ) with at least one booster housing section ( 3 ) including an opening ( 13 ) into which a sealing element ( 1 ) made of a flexible material is mounted, said sealing element ( 1 ) including a recess ( 10 ) into which a pneumatic connecting element ( 5 ), in particular for the vacuum supply of the brake booster ( 1 ), is slidable. An object of the present invention is to precisely define the exit portion ( 9 ) of a deflected connecting element ( 5 ) in its rotational position relative to the housing ( 3 ) of the booster in order to simplify and improve the assembly. This object is achieved in that associated projections ( 6 ) and recesses ( 7 ) are used to ensure that the connecting element ( 5 ) can only be mounted into the sealing element ( 1 ) at the correct angle.

[0001] The present invention relates to a brake booster for a motor vehicle with the features of the preamble of patent claim 1.

[0002] A brake booster of this type is e.g. disclosed in the applicant's Brake Handbook, edition 9.1, page 101, FIGS. 1 to 3. Said booster comprises at least one booster housing section with an opening housing a sealing element made of a flexible material and including a pneumatic connection that can be slid into a recess of the sealing element. Said pneumatic connection may e.g. be a simple pneumatic connection or a construction unit composed of a pneumatic connection with an integrated non-return valve. The connection is preferably used for the vacuum supply of the brake booster.

[0003] Various car manufacturers fit the pneumatic connection in their own premises for different reasons. Due to space problems it is necessary that the connecting element extending at an angle in many cases is mounted in a defined angular position in order that the supply conduits are safely connected, rubbing or scuffing on other assemblies in the engine compartment is prevented, and technical problems or space problems are ruled out.

[0004] In view of the above, an object of the present invention is to provide a brake booster that permits being completed, with low effort, only in the plant of the car manufacturer, meaning that it can be equipped with the necessary pneumatic connections, and the direction of the exit portion of the connecting hoses is exactly predefined.

[0005] This object is achieved in a brake booster of the type to be taken from the preamble of claim 1 by employing the features indicated in the characterizing portion of claim 1. Thus, the solution of the object of the invention principally resides in providing the connecting element and the sealing element with respectively associated projections and recesses so that they fit to one another only in a defined angular position of the connecting element relative to the sealing element. Only in this position is it possible to joint the two parts, for example, by locking them. Not only do the features of the invention render it possible to prevent jointing the connecting element and the sealing element at a wrong angle. Additionally, the two last mentioned components are also secured against twisting because engaging projections and recesses achieve undercutting surfaces that prevent the two components from twisting in relation to each other.

[0006] The combination of features according to claim 2 is advisable as an improvement of the invention to enhance the torsional strength of the connecting element with respect to the housing of the brake booster and also secure the angularly correct mounting position of the sealing element in relation of the housing of the brake booster.

[0007] A second, equivalent solution of the object of the invention is achieved by the combination of features apparent from the characterizing portion of claim 3. This solution principally involves providing the connecting element and the housing section with respectively allocated projections and recesses so that these fit together only in a defined angular position of the connecting element relative to the housing section. Only in this position is it possible to joint the sealing element and the connecting element, e.g. by locking, because the connecting element can be inserted sufficiently deeply into the sealing element only in this angular position. With the features of the invention, it is not only possible to prevent jointing the connecting element and housing section at a wrong angle. The two last mentioned components are additionally secured against twisting relative to each other because engaging projections and recesses achieve undercutting surfaces that prevent the two components from twisting relative to each other. The anti-rotation mechanism of the connecting element relative to the housing also determines the angular position of the exit portion of the connecting element.

[0008] The recess in the housing section is offset relative to the center line of the opening in the housing section. In this arrangement, the recess in relation to the center line may basically be offset in circumferential direction or in radial direction. When the recess extends in circumferential direction, it is advisable for the recess to have a trough-shaped configuration because in this case the material of which the housing section is made will not deform considerably. Another favorable improvement with respect to the arrangement for the recess is indicated in the combination of features noted in claim 4. For example, the arrangement may be placed in the area of a circumferential depression in the housing section. It is recommended in a favorable improvement of the invention to employ the combination of features according to claim 5 when the recess adopts a radial position relative to the recess. This applies in particular when implementing the features of claim 6 because this particularly minimizes the deformation work in the housing section.

[0009] Further details of the present invention can be taken from the description and the accompanying drawings. The invention will be described in more detail in the following by making reference to the accompanying drawings showing a preferred embodiment. In the drawings,

[0010]FIG. 1 is a top view of a cutout of the housing with an inserted sealing element and connecting element.

[0011]FIG. 2 is a section taken through the arrangement of FIG. 1 in the center plane of the angled connecting element.

[0012]FIG. 3 is a perspective view of the section taken through the illustration of FIG. 2.

[0013]FIG. 4 is a perspective view of the sealing element, as seen from the housing.

[0014]FIG. 5 is a cutout of the housing, viewed from the inside.

[0015]FIG. 6 shows the connection of the sealing element and housing section according to FIGS. 4 and 5.

[0016]FIG. 7 shows the connection of the connecting element, sealing element, and housing.

[0017]FIG. 8 is a cross-section taken through the connection of FIG. 7.

[0018]FIG. 9 is a cutout of a spatial illustration of the housing with a second embodiment.

[0019]FIG. 10 is a top view of FIG. 9.

[0020]FIG. 11 is a cross-section taken along line A-A in FIG. 10.

[0021]FIG. 1 shows a top view of a cutout of housing 3 of the brake booster in which sealing element 1 is inserted, with connecting element 5 inserted in turn into sealing element 1. Connecting element 5 has an angled exit portion 9 which shall be mounted in a predetermined angular position of its longitudinal axis with respect to the housing 3, as defined in the object of the invention.

[0022] The desired rotational position of the connecting element 5 in relation to the sealing element 1 is achieved by means of a second projection 6 engaging an associated first recess 7 in the sealing element 1. The second projection 6 configured as a projecting nose is designed to have such a length that safe locking is only possible if the nose 6 engages the recess 7. The sealing element and the connecting element are lockable relative each other by means of prong-shaped projections 10. A console 11 at the connecting element 5 determines the distance of the connecting element from the sealing element 1 and, hence, from the housing 3. Housing 3 includes a rim 12 formed inwards and confining opening 13. This improves taking up radial forces, without cutting the sealing element. Furthermore, this increases the mutual radial abutment surface of sealing element and housing 3, thereby improving the frictional engagement against twisting.

[0023] FIGS. 4 to 6 show a cutout of the housing 3, the sealing element 1, as well as the connection between these two elements. Sealing element 1 is equipped with two opposed, symmetrically designed third projections 2 that are appropriate to engage associated third recesses 4 in housing 3. FIG. 6 shows the two jointed elements that are protected against twisting relative to one another by engagement of third projections in third recesses. Of course, the third recesses and projections can be configured so that only one single mutual angular position permits connecting the two above-mentioned elements. This may e.g. be forced by the provision of only one single third projection and one single associated third recess, or by the unsymmetrical arrangement of third projections and recesses over the periphery of opening 13.

[0024] Finally, FIGS. 7 and 8 show the assembly of housing 3 with sealing element 1 and connecting element 5. Corresponding provisions in the manufacture of the housing 3 including the sealing element permit ensuring that the sealing element is mounted in the housing only in one defined angular position, even if the third recesses of the sealing element are placed symmetrically for reasons of manufacture.

[0025] In an improvement of the invention, the connecting element may include a non-return valve or be configured as a connection piece of a hose.

[0026]FIG. 9 shows a perspective view of a cutout of part of housing 3, which is provided with a bulge 16. Several bulges of this type are arranged on the periphery of housing 3, e.g. in order to receive a sensor. The housing has substantially the shape of a bowl, with bulge 16 arranged at the edge of the bottom of the bowl. A recess 7 is shaped in bulge 16 so that said bulge generally has the shape of a U. A projection 6 of the connecting element 5 projects between the legs of the U-shaped bulge, the end of projection 6 being received in recess 7. Thus, the end of projection 6 is seized between the lateral walls of recess 7 so that the projection 6 can no longer rotate about the longitudinal axis of the connecting element 5, and the rotational position of the connecting element 5 is thereby defined. However, when the connecting position of the connecting element is defined, the angular position of the exit portion 9 is defined as well, which is integrally connected with projection 6.

[0027] It is also possible to seize the end of projection 6 in a recess that extends in a circumferential direction on the bottom of the housing. In this case, the recess in the housing should be shaped roughly like a trough.

[0028]FIG. 10 shows an enlarged top view of the illustration of FIG. 9.

[0029]FIG. 11 shows a cross-section taken along line of intersection A-A in FIG. 9. Corresponding to FIGS. 1 to 9, opening 13 in housing 3 can again be seen, into which sealing element 1 along with connecting element 5 is inserted. The anti-rotation mechanism in the present case is not established between the connecting element and the sealing element, but between the connecting element 5 and the housing 3. Line 18 indicates that the bottom of the housing 3 is per se conically inclined. Projection 6 still includes a nose 19 that protrudes into recess 7 of the housing. As the surroundings laterally of the recess 7 are much higher than the bottom of recess 7, it is possible to insert the connecting element 5 with the sealing element 1 into opening 13 only when the nose 19 plunges into recess 7. The rotational position of the connecting element 5 in relation to housing 3 is fixed this way.

[0030] FIGS. 9 to 11 still show a depression 17 that serves to reinforce the housing 3. It is per se also possible to add a recess corresponding to recess 7 to the depression and thereby define the rotational position of the connecting element 5. However, the deformation work necessary for producing the recess is considerably reduced at the chosen location close to the lateral wall 20 of housing 3 so that the recess is advantageously provided at this location. This is essentially achieved because the recess may be kept open towards the outside in this case, thereby obviating the need for a radially outwards disposed lateral wall of the recess. 

1. Brake booster with at least one booster housing section (3) including an opening (13) into which a sealing element (1) made of a flexible material is mounted, said sealing element (1) including an opening (10) into which a pneumatic connecting element (5), in particular for the vacuum supply of the brake booster (1), is slidable, characterized in that the sealing element (1) includes at least one first projection and/or one first recess (7) and that the connecting element is provided with at least one second recess and/or second projection (6) associated with the first projection or the first recess in such a manner that the associated projections (6) and recesses (7) engage each other only in a defined angular position between sealing element (1) and connecting element (5), thereby allowing lock-type jointing of the sealing element (1) and connecting element (5).
 2. Brake booster as claimed in claim 1, characterized in that the sealing element (1) includes in each case at least one third projection (2) and/or one third recess, and that the opening (13) includes at least one associated fourth recess (4) and/or fourth projection in such a manner that the associated projections (2) and recesses (4) engage each other only in a defined angular position between sealing element (1) and opening (13), thereby allowing jointing the sealing element (1) and the opening (5)* (*translator's note: the correct reference numeral is ‘13’).
 3. Brake booster with at least one booster housing section (3) including an opening (13) into which a sealing element (1) made of a flexible material is mounted, said sealing element (1) including an opening (10) into which a pneumatic connecting element (5), in particular for the vacuum supply of the brake booster (1), is slidable, characterized in that the booster housing section (3) includes at least one first projection and/or one first recess (7), and that the connecting element (5) includes at least one second recess and/or second projection (6) associated with said first projection or said first recess in such a fashion that the associated projections (6) and recesses (7) engage each other only in a defined angular position between the booster housing part (3) and the connecting element (5), thereby allowing jointing the sealing element (1) and the connecting element (5).
 4. Brake booster as claimed in claim 3, characterized in that the housing section (3) is substantially bowl-shaped, wherein opening (13) is provided in the bottom of the bowl and wherein the recess in the housing section (3) is now arranged radially offset relative to the opening (13).
 5. Brake booster as claimed in claim 4, characterized in that the recess (7) is arranged at the housing section (3) radially outside in the fringe area of the bottom.
 6. Brake booster as claimed in claim 5, characterized in that the recess (7) is arranged radially outside at the bottom in such a manner that it extends until the abutting surface between the bottom and the peripheral surface (20) of the bowl.
 7. Brake booster as claimed in claim 6, characterized in that the recess (7) forms a radially extending groove that is open in the direction towards the peripheral surface (20) of the bowl. 